Precision barrel nut from NSS

[Ratbuster]

In the past I have purchased ground recoil lugs and the aftermarket barrel nut from Northland SS for builds where I am going for precision shooting. I believe ground lug is important. What about the barrel nut? How important is it to go with the better nut? Are the factory barrel nuts a bad choice?

[Robinhood]

IMHO everything true is moving towards precision. you are correct about the ground lug due to the factory ones needing as much as .020" to get cleaned up on the Blanchard. As for the NSS nut, how do we know the factory ones are not just as true? Try putting some 600 grit on a clean flat surface and using light pressure rub some small figure 8's with the face of your nut.

You will realize the accuracy potential when you have the face of the action trued. For ultimate precision you need to have the threads trued to the centerline of the action and the barrel indexed with the bend of the bore to the vertical axis of the action. It would not hurt to have the mount holes redrilled with the centerline as well. You would probably go with a custom if you needed that kind of tool though.

[Dave Hoback]

IMHO everything true is moving towards precision. you are correct about the ground lug due to the factory ones need as much as .020" to get cleaned up on the Blanchard. As for the NSS nut, how do we know the factory ones are not just as true? Try putting some 600 grit on a clean flat surface and using light pressure rub some small figure 8's with the face of your nut.

You will realize the accuracy potential when you have the face of the action trued. For ultimate precision you need to have the threads trued to the centerline of the action and the barrel indexed with the bend of the bore to the vertical axis of the action. It would not hurt to have the mount holes redrilled with the centerline as well. You would probably go with a custom if you needed that kind of tool though.

What he said! Very well explained. Very simply, a precision machined barrel nut is just cheap insurance! Either NSS or PTG if you want chrome- moly steel. What are they, $24-$30? Versus like $10 for a stock cast Savage bolt? That is a very simple answer to me. Honestly, they are even more attractive.

[Keith_A]

IMHO everything true is moving towards precision. you are correct about the ground lug due to the factory ones need as much as .020" to get cleaned up on the Blanchard. As for the NSS nut, how do we know the factory ones are not just as true? Try putting some 600 grit on a clean flat surface and using light pressure rub some small figure 8's with the face of your nut.

You will realize the accuracy potential when you have the face of the action trued. For ultimate precision you need to have the threads trued to the centerline of the action and the barrel indexed with the bend of the bore to the vertical axis of the action. It would not hurt to have the mount holes redrilled with the centerline as well. You would probably go with a custom if you needed that kind of tool though.

Hey Robinhood,
You're absolutely correct about the face of the Barrel Nut not being absolutely flat! "Polishing" the nut face on a known flat surface (like a piece of window glass or plexiglass) really does show the slight surface variation (and considerably reduces it). The same thing is true of the Receiver face (that mates with the Lug). Polishing that will also produce a flatter surface.
Keith

[Robinhood]

The same thing is true of the Receiver face (that mates with the Lug). Polishing that will also produce a flatter surface.
Keith

I agree Keith. I use a Norton combination round hone for this job. I set it on my table fine side up, add some oil and go slow and steady. but for someone who does not have one the other method is more difficult but equally functional.

[7887mm08]

lapping the face of the nut does absolutely nothing if the threads are not perpendicular to the face.

[Robinhood]

This is true to a great extent. It does do something. It gives you flat surfaces that mate up to each other which will aid in improved accuracy. It is not guaranteed to improve precision. We know for that you must have everything in the same axis and perpendicular. That was in Post #2.

[dfrosch]

This is true to a great extent. It does do something. It gives you flat surfaces that mate up to each other which will aid in improved accuracy. It is not guaranteed to improve precision. We know for that you must have everything in the same axis and perpendicular. That was in Post #2.

Yep. The very slight clearance between male and female threads allows for a tiny perpendicularity error. But the flatter the face, the less chance of vibration.

Something else that I need to mention. On my very first build about eight years ago, the ground recoil lug had a screw for a location pin. The head of that screw was about .005 taller than the receiver slot depth. So the pin bottomed out before the receiver face mated with the recoil lug. Had to grind on the screw head and file on the slot to get decent groups.

[J.Baker]

If you need a barrel nut (meaning you don't have one), then by all means get the trued one if you like. If you already have a nut and are wondering if the trued nut is worth getting, I would say no. Easy enough to true the one you already have if you're so inclined.

[Robinhood]

Something else that I need to mention. On my very first build about eight years ago, the ground recoil lug had a screw for a location pin. The head of that screw was about .005 taller than the receiver slot depth. So the pin bottomed out before the receiver face mated with the recoil lug. Had to grind on the screw head and file on the slot to get decent groups.

Nice dfrosch. I fit every one I do. Depth and width. never thought to mention that.